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E.O. Udegbunam

Publications and source records attributed to E.O. Udegbunam.

2 recordsLinked to original sources

A FORTRAN program for interpretation of relative permeability from unsteady-state displacements with capillary pressure included

This paper presents a FORTRAN program for the determination of two-phase relative permeabilities from unsteady-state displacement data with capillary pressure terms included. The interpretative model employed in this program combines the simultaneous solution of a variant of the fractional flow equation which includes a capillary pressure term and an integro-differential equation derived from Darcy's law without assuming the simplified Buckley-Leverett flow. The incorporation of capillary pressure in the governing equations dispenses with the high flowrate experimental requirements normally employed to overcome capillarity effects. An illustrative example is presented herein which implements this program for the determination of oil/water relative permeabilities from a sandstone core sample. Results obtained compares favorably with results previously given in the literature. ?? 1991.

Computers & Geosciences↗

Assessing the effects of microbial metabolism and metabolities on reservoir pore structure

The effect of microbial treatment on pore structure of sandstone and carbonatereservoirs was determined. Understanding how different bacterial strains and their metabolic bioproducts affect reservoir pore structure will permit the prudent application of microorganisms for enhanced oil recovery. The microbial strains tested included Clostridium acetobutylicum, a polymer-producing Bacillus strain, and an unidentified halophilic anaerobe that mainly produced acids and gases. Electrical conductivity, absolute permeability, porosity and centrifuge capillary pressure were used to examine rock pore structures. Modifications of the pore structure observed in the laboratory cores included pore enlargement due to acid dissolution of carbonates and poare throat reduction due to biomass plugging. This paper shows that careful selection of microbes based on proper understanding of the reservoir petrophysical characteristics is necessary for applications of microbially enhanced oil recovery. These methods and results can be useful to field operators and laboratory researchers involved in design and screening of reservoirs for MEOR. The methods are also applicable in evaluation of formation damage caused by drilling, injection or completion fluids or stimulation caused by acids.

Conference Paper↗